#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>

int main(int argc,char*argv[])
{
  pid_t id=fork();
  if(id==0)
  {
      execl("/usr/bin/ls","ls",NULL);
  }
  pid_t rid=waitpid(id,NULL,0);
  if(rid>0)
  {
    printf("wait success\n");
  }
  return 0;
}
